In the field of hydrocarbon exploration and recovery, holes (wellbores, boreholes) are drilled deep into the crust of the earth to access deposits of fluid hydrocarbons. The degree of fluidity and the makeup of deposits varies, it is desirable to have the ability to control flow from different deposits into the wellbore. Flow control devices are varied in nature and in their particular construction but all must be actuatable from a remote location, such as a surface location, to be of use to a well operator. One common configuration for remote actuation of a downhole device such as a flow control device is a pair of hydraulic control lines. One of the lines is employed to force the flow control device to an open position while the other is employed to force the device to a closed position. While such systems work well for their intended purpose, it is axiomatic that a number of flow control devices each having a pair of hydraulic control lines is problematic with respect to the number of control lines that would ultimately need to reach the location intended for remote control (e.g. surface). All such control lines would need to extend through a borehole that in most instances is 9⅝% inches in diameter. Large numbers of control lines in such a small diameter borehole take up space where space is at a premium. This is not an advantageous situation.
While the art has proposed several remedies for this issue, each is complex, adds cost, adds potential for malfunction and is overall not a panacea. The art is therefore still in need of a configuration and operative modality for flow control valves that reduces the number of necessary hydraulic control lines while maximizing the number of devices controllable thereby and while maintaining simplicity and cost efficiency of design.